The invention relates to an arrangement with a joint and a gearwheel body for a transmission, wherein the joint is arranged at least partially in an interior space enclosed by the gearwheel body.
An arrangement conforming to its genre is described, for example, in German patent specification DE 199 04 960 C1. The joint that is disclosed in said patent involves, in particular, a universal joint. Such universal joints are inserted, for example, in skew bevel gears of transfer cases and welded thereto. In addition to the asynchronism, there is the drawback that such universal joints cannot withstand the torque loads to be expected in future engines of motor vehicles.
The object of the present invention is to propose an arrangement of gearwheel bodies and joints that also allows the transmission of higher torques.
This engineering object is achieved, according to the invention, by the fact that the joint is a constant velocity joint. In this case the gearwheel body is, in particular, a part of the transmission.
One embodiment comprises that the joint (i.e. the constant velocity joint) has an inner hub with a longitudinal axis and inner ball tracks; that the joint has an outer hub with a longitudinal axis and outer ball tracks, wherein the inner ball tracks and the outer ball tracks are arranged in pairs in relation to each other; that the joint has a cage with windows that are distributed over the periphery; that the cage is arranged between the inner hub and the outer hub; that the joint has balls, which are arranged in the windows of the cage and in the pairs of the inner ball tracks and the outer ball tracks and which are held in a plane by the cage, wherein the tangential planes at the points of contact of the balls with the inner ball tracks and the outer ball tracks form a control angle, wherein the inner ball tracks have in each case an active section, in which the balls move, and wherein the outer ball tracks have in each case an active section, in which the balls move.
One embodiment provides that at least the active sections of the inner ball tracks have in each case a curvature that in essence changes continuously along the associated longitudinal axis, that at least the active sections of the outer ball tracks have in each case a curvature that in essence changes continuously along the associated longitudinal axis, and that the curvature of the active sections of the inner ball tracks and the curvature of the active sections of the outer ball tracks are designed and adapted to each other in such a way that the control angle is essentially constant at least between the states of the totally extended joint and the maximally deflected joint. As a result, the curvature of the tracks changes along the longitudinal axis of the respective hub. See in this respect U.S. Pat. No. 8,523,687, corresponding to German patent application DE 10 2010 027 059.8, which was filed by the applicant and is not a prior publication. The track curvatures of this special joint are designed in such a way that when the joint bends, the control angle remains constant as compared to the prior art.
The following embodiments relate, in particular, to the aforementioned special constant velocity joint. One embodiment provides that the inner ball tracks have in essence completely a curvature that in essence changes continuously along the associated longitudinal axis. Thus, the continuous curvature also relates, for example, to regions, in which the balls may be located only during the assembly of the joint. One embodiment comprises that the outer ball tracks have in essence completely a curvature that in essence changes continuously along the associated longitudinal axis. In this embodiment the same also applies to the outer ball tracks having a curvature that changes continuously over its entire course. One embodiment provides that at least the active sections of the inner ball tracks extend in a plane with the associated longitudinal axis. As a result, the active ball tracks have no lateral offset over their entire course. One embodiment comprises that the inner ball tracks extend in essence completely in a plane with the associated longitudinal axis. One embodiment provides that at least the active sections of the outer ball tracks extend in a plane with the associated longitudinal axis. In this embodiment the outer ball tracks are in alignment with the longitudinal axis of the outer hub. One embodiment comprises that the outer ball tracks extend in essence completely in a plane with the associated longitudinal axis. One embodiment provides that the curvature of the active sections of the inner ball tracks and the curvature of the active sections of the outer ball tracks follow the same mathematical function. In this embodiment the ball tracks that are assigned to each other in pairs are uniform. One embodiment comprises that the curvature of at least the active sections of the inner ball tracks and/or the curvature of at least the active sections of the outer ball tracks can be described at least approximately by a mathematical function that is linear at least in sections. One embodiment provides that the curvature of at least the active sections of the inner ball tracks and/or the curvature of at least the active sections of the outer ball tracks can be described at least approximately by a mathematical function that is elliptical at least in sections.
One embodiment comprises that an outer side of the outer hub is in contact with an inner side of the gearwheel body at least by means of a press fit and/or form fit.
One embodiment provides that the outer hub is arranged, in particular, is fixed, between a shoulder of the gearwheel body and a bearing cover. In this embodiment the inner side of the gearwheel body has a shoulder, against which the outer hub of the joint rests with one side. On the other side of the outer hub there is a bearing cover, which in this embodiment also closes off one side of the arrangement or specifically the gearwheel body. At the same time, for example, the inner hub or a shaft, which is connected to the inner hub, projects from the bearing cover.
One embodiment comprises that the bearing cover has a nose, which faces the outer hub and which is, in particular, elastically deformable or plastically deformable or resilient. In this embodiment the bearing cover has an extension, which acts preferably as a stop for the outer hub. In this case the nose can be deformed or reformed in an elastic or plastic manner, for example, during the assembly. Preferably the nose is deformed outwards, i.e. in the direction of the gearwheel body. In an additional embodiment the nose is designed in such a way that it is resilient. With this nose it is possible, for example, to compensate for the tolerances of the components.
One embodiment consists of the fact that the gearwheel body and the bearing cover are connected to one another, in particular, are welded to one another. One design variant provides, in particular, that the welding of the gearwheel body with the bearing cover entails a pressing of the gearwheel body and the bearing cover against each other with a concurrent welding. In this embodiment the gearwheel body and the bearing cover are welded to one another, whereby in one embodiment an axial pressure is exerted during the welding so that the gearwheel body and the bearing cover are pressed against each other.
One embodiment provides that the outer hub is arranged, in particular, is fixed, between a shoulder of the gearwheel body and a bead of the gearwheel body. One design variant provides, in particular, that the bead of the gearwheel body is produced after the outer hub is inserted into the interior space of the gearwheel body. In this embodiment the outer hub is clamped between the stop of the gearwheel body and a bead of the gearwheel body, wherein the bead is produced preferably after the outer hub is inserted into the interior space of the gearwheel body. That is, on the side of the bead the material of the gearwheel body is plastically defined and is deformed, in particular, in the direction of the interior space. For this purpose it is provided, for example, that the gearwheel body is not yet hardened following the insertion of the outer hub and prior to the production of the bead. In this design variant, for example, at least the outer hub and the gearwheel body are hardened first in the assembled state. In one design variant at least one component, for example, the outer hub, is already partially pre-hardened.
One embodiment comprises that at least one sealing element is provided. This sealing element is arranged between the outer hub and the bearing cover and opens out on the inner hub and/or an extension of the inner hub. One embodiment provides that the sealing element, for example, a bellows, is pressed between the outer hub and the bearing cover and has elastic properties, i.e. can be mechanically loaded.
One embodiment provides that a closing element, in particular a sheet metal hat, is provided on a side of the joint that faces away from the bearing cover. In this embodiment the side of the inventive arrangement that faces away from the bearing cover or more specifically the side of the gearwheel body that faces away from the bearing cover is at least partially closed by a closing element. In this case, it involves, for example, a type of sheet metal hat having a cylindrical construction that is inserted into a recess of the gearwheel body.
One embodiment comprises that a fill element, in particular a closed cell fill element, is arranged in at least one cavity of the arrangement. In this case one design variant provides that the fill element, for example, a foam element, is arranged on the side of the outer hub that faces the sheet metal hat. In this embodiment an interior space of the arrangement is populated with a fill element, for example, an element made of foam. Preferably the material that is used is stable with respect to lubricants and with respect to temperature. The fill element reduces the space which exists around the joint and which is filled, for example, with lubricating grease so that the joint will function reliably. A cavity can be produced, for example, by a light-weight construction of the arrangement and, in particular, if the outer dimensions of the arrangement or more specifically the components of the arrangement are maintained.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.